A substrate with built-in electronic component, in which electronic components are stored in a cavity of a core layer, includes a core layer including a core material and a cavity formed by penetrating the core material, electronic components stored in the cavity, an insulating material that fills a gap between the cavity and each electronic component, and an insulating layer formed on the core layer and including a ground wiring, a signal wiring, and the like. The substrate with built-in electronic component has a structure in which the electronic components stored in the cavity are connected to those wirings.
In a major substrate with built-in electronic component in related art, one electronic component is stored in one cavity. In recent years, an attempt to store a plurality of electronic components in one cavity has been made for the purpose of reducing the number of electronic components to be mounted on a surface of the substrate with built-in electronic component.
For example, Japanese Patent Application Laid-open No. 2009-081183 discloses that a capacitor unit in which external electrodes of a plurality of capacitors are connected to be integrated is stored in a cavity of a core substrate. In this technique, the capacitor unit should be preliminarily manufactured before the external electrodes are stored, which is burdensome. In addition, when the arrangement of the capacitor unit in the cavity is changed, the arrangement of all the capacitors that constitute the capacitor unit is changed accordingly. Consequently, the degree of freedom in arrangement (degree of freedom in position or orientation) is lower compared with the case where the capacitors are individually stored. In contrast, Japanese Patent Application Laid-open No. 2006-129448 discloses that a plurality of active components, passive components, or active and passive components are stored in a concave portion of a support. In this technique, the positions or orientations of the stored components are not taken into consideration, and thus there may be a possibility that mutual interference such as crosstalk is caused between the adjacent components.